Automatic telephone-exchange system.



A. E. LUNDELL.

. AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED IUNEZB. 1915.

PantedTJune 19, 1917:

PIII..

ALBEN E.- LUNDELL, OF NEW YORK, N.'Y., ASSIGNOR, BY MESNE ASSIGNMENTS, T0 WESTERN ELECTRIC COMPANY, INCORPGRATED, A CORPORATION E NEW YORK.

AUTOMATIC TLEEHGNE-EXCHNGE SYSTEM.r

Specification of Letters etent. Patented Jun@ 19,1 7). v

i Application filed Iune28, 1915. Serial No. 36,738.

10 all whom t may concern:

Be it known that l, 'ALBEN E. LUNDELL, l

a citizen of the United States, residing at New Yorlr, inthe county of Bronx und State of New York, 'have invented certain new and useful Improvements in Automaticy Telephone-Exchange Systeins, of which the following 1s a full, clear, concise, und' exact description.

This invention relates to automatic tele-y phone exchange systems, andI more particuto. circuit arrangements for `selector switches utilizedl such' systems,

lai-ly The object of this inyentionv ltoprovide a circuit errungement`y for 'insuring the proper andv quick operation of the' selector switches.

In automatic telephone exchnges there is associated with the selector switclr an iin-y pulse receiving mechanism, such as a line relay, for repeating to the electromagnetic Operating ineans, such as a steppingF magnet, the impulses sent out from the Vfsurbsoribers or other sending station.. lliere` nifty be further associated with suchy 4 switches a steeringr f nieclu'inisiii, suchy as side switch, for controlling the circuits. Aln

i order to prevent the untimely actuation 4of the stepping magnet, it has been proposed` to maintain the sainefnormally disconnected from the controlling Contact of the line re-. ley and connect it thereto only :ifterthe switch is ready to vbe set in accordance with the impulses. rlhis has been :icccniplished by completing the circuit of the stepping magnet only in an operating, for instance'` the second, position of the sidel switch 'howf ever, in systems heretofore proposed l'a sutil` -cient timelielepsed during the movement of;v

the side sitch wipers'if'roin the normal to the peratng position 'to make possible loss of an iiiipulse or iinpulsesi f According 4 to the mein feature ofthis Ain-y vention, the steering mechanism or side switch is moved from its normal to its operoting position upon the iirst actuation of 'the impulse receiving; rneehzinisni or line re lay. As the actuation of the line relay ocof current impulses getting lost is reduced to a minimum. f

The drawings represent dingrammeticillly i :i telephone exchange system, only' so much being shown of the circuit arrangements and selector f the ` rection.

apparatus as is necessary for a cie-ar' Lindenl standing of this invention 1- The mechanical construction and the op'eiation of the. selector switches and other appu-l rutus used lu the building up of a coniiec' tion between u calling-and a called line uref wclliinowii to those skilled in the ai'tand, ytluiretorc,y in' the following, a detailed de f scriptioii will be I:given only of the ope-ration of a selector switch utilized in the estab-y lishment ofl a connection.

The subscriber at substation l, desiring to establish u connection with substation 2, ,ree

' niov'esliis receiverffioin the switchhook and causes in the \.'ell-kiiouui manner a trunk luider or line switch 3 to select an idle trunk leading to a selector switch -l ,As soon as the wipers of switch 3 are set on the terininals of un idle trunk,l a circuit is" closed from grounded buttery 5 tlirough'tlie lefthand winding of a line relfiy, wiper -7 of u 'steering vor side-switch associatedwith selector el, the loop of the calling subst-ution 2, side-s Yitch wiper 8 and the rightliand wii'idino;l of relay 6, toground. Relay' (3 upon energizntion closes a circuit `from ,Q'round through .its arnuiture and front contact, side-switch wiper 11, und the winding i ,of a quick acting escapenient magnet 12, to

grounded buttery {Upon the energizetioii of the 4es Liy'ieiiientinegriet l2, thewipcrs of the side-switch associated vwith selector 4 are inoved into vtheir second or operating position. The callingl subscriber' proceedsnow to cause the setting" of selector switclr 4 by operating;` his culling' dial 2O provided utv substation l rior interrupting the line cir-- cuit u desired iuunber or' times. Upon each interruption of the line circuit, line relay 6 releases its armature and closes a circuit for the primary operating magnet 15,' Awhich armature oic relay 6, to ground. i

Due to the slowness of relay I6' to pull up during the vibration of the armature of relay 6, relayl will not become energized; As soon,`horvever, ns the/sending out-ofI impl'llses cerises und the urmziture of 'line' 110 relay 6 is maintained etti-acted, a circuit is Y contact Zn' until selector switch closed from ground, through the armature and front contact of relay 6, side switch wiper 11, contact 21 (closed as soon as the brushes of selector switch it leave their normal position), and the left-hand winding ot slow-acting relay 16 to grounded battery Q2. Relay 1G becomes energized, disconnects magnet 15 and closes a circuit from grounded battery 13 through the winding of escapement magnet 12, left-hand armature and front contact of relay 16 and front contact and armature of relay 6, to ground. The escapement magnet moves the` side-switch wipers into position 3, in which position a `circuit is closed from ground, through interrupter 23, side-switch wiper E24 and the winding of a secondary or vertical stepping magnet 25, to grounded battery 14.' Under the control of magnet Q5, the wipers of the selector switch are stepped in a vertical direction until an idle trunk is reached. `When the side-switch wiper 11 is moved out of its second position, relay 16 becomes deine-rgized an(l opens thc circuit of escapement magnet 1&2. As soon as test brush QG of selector switch 4 reaches the terminal of an idle trunk (i. e., one to which ground is connected), a circuit is closed from this ground connection through brush Q6 of selector 4, conductor 27, side-switch wiper 30, the back contact and lett-hand armature. of relay 16, and the winding of eseapement magnet 1:2, to grounded battery 13. As long as wiper 96 travels over terminals ot' busy trunks, no such ground connection is found for the escapement magnet and therefore this magnet. remains denergized. rlhe magnet 12 upon encrgization causes the wipers ot' thev side-switch to move into position l. in which position the calling substation line is extended through the wipers T and S ot' the side-Twitch to :mother switching mechanism provided between Se.- lector I and thecalled substation 2, and under the control ot' substation 1 the desired connection may be established in the wellknown manner.

lpon the severing ot' the connection a ground is sent l'rom the above mentioned switching mechanism through wiper 26. conductor 27. armature and hach contact of magnet t2. (this magnet being deinergized in the fourth position ol' the side-ruvitch)` side-switch wiper 2&1 and the winding ot release magnet 1&2, to grounded batter)v 33. ltelease magnet 312, upon energization. closes a locking circuit 'or itselt' t'rom grtutnded batter)v through its winding and contact Ill. and ott-normal contact 35 ot` selector switch t to ground. llnder the control of the release magnet Irl the selector switch -t alul the associated side-switch will be re stored to normal. the locking circuit otl the release magnet being maintained closed at. l has been restored to its normal position. After theV side-switch has been restored to normal and the receiver at calling substation 1 has been hung up, a ground is sentil through the armaturc and back contact of relay 6, side-switch wiper 17 and otinormal contact 36 to the trunk finder 3, -t'or causing the release of this switch.

Should the subscriber at substation 1 abandon the call before sending out impulses, he would hang up his receiver and cause thereby the denergization of relay 6. A circuit would 'be closed thereupon from ground through the armature and back contact of relay 6, the side-switch wiper 17 (which is now in position 2), and the righthand winding of slow-acting relay 16, to

grounded battery 22. The slow-acting relay 16 by pulling up its armature closes a. circuit from grounded battery 33 through the winding of release magnet 89. the back contact and right-hand armature of slow-acting relay 16, the side-switch wiper 1"` and the back Contact and armature of relay 6, to ground. The release magnet 3Q causes the restoration of the employed switching mechanism in the same manner as above described.

If the subscriber at substation 1 abandons the call in position 3 of the side-switch wipers, that is to say, after the operation of magnet 15, the release would be accomplished in the same manner as in the last mentioned case.

What is claimed is:

1. In a telephone exchange system, incoming lines and outgoing lines, a selector switch for extending an incoming line toward an outgoing line, an impulse receiving mechanism associated with said selector switch. a. normally disconnected electromagnetic, means controllable by said impulse recei ving meehanisn'i for operating Said selector switch, two magnets, and means for con necting linto circuit said electromagnetic means upon the first operation of one ot said magnets while the other one of said magnets is in normal condition.

2. ,Tn nl telephone exchange system, incoming lilies and outgoing lines, a selector switch tor extending an incoming line to-l ward an Aoutgoing line, a line relay associated with said selector switch, a normally disconnected electromagnetic means controllable by said line relay for operating said selector switch` a quick and a slow acting elect-romagiut and means for connecting into circuit said electromagnetic means upon the trst actuation of said quick acting mag net, while said slow-acting magnet romains in normal condition.

ln a telephone exchange system. ineomf inglines and outgoing lines. a selector' switch l'or extending an incoming line toward an outgoing line, a line relay asso-- ciated with said selector switch, a normally for connecting into circuit said clectromog disconnected electromagnetic means con- 4natio means upon the first actuation of said trollablo byy sa line relay for opeating quckacting magnet Whic'sa slow acting 1@ said selector switch, a quick and a, slow act magnet is in normal condition.

5 ing electromagnct, moans operativo upon j n witness whclreof.2 hereunto subscribe vthe first actuation of salfzfl'me remy for op .my mme this 25th da f of Juno, A. H1915.

erating smd quick acting magnet, and means ALB 1N E. LUNDELJ. 

